With a surface area of about 1.5 to 2.0 m2, the human skin is the human organ with the largest surface area that performs vital functions for the body. For this, the skin contains blood and lymph vessels, through the walls of which the exchange of lymphatic fluid, gases, nutrients and waste materials can take place in order, for example, to ensure nutrition and metabolism. Other functions of the skin are the regulation of body temperature, protecting the body against dehydration and against external mechanical, chemical and bacterial action. In doing so, the secretions of skin glands keep the skin supple and help in regulating the water balance of the skin. In addition, the skin provides the organism, among other things, via free nerve endings, with tactile, heat and cold and pain stimuli and thus has the function of a sensory organ.
The various products offered for hygiene, personal care and cosmetics, such as, for example, skin cleansing, skin protection and skin care products, are therefore not only just for the cleansing, protection and care of the skin, but they also provide a quality of life and ensure the well-being of the person.
As a body shell, the human skin represents the connection with, but at the same time also the delineation of the human body from its external world. In particular, it provides the means of contact with everything that the human organism needs to live—but also what may endanger it.
Therefore, it is especially important to care for the human skin and to protect it from environmental influences. The past history of skin care products can therefore be traced far back into the history of human development itself. As the requirements for skin care products can be very different, the range of different skin care products grew wider over the years in order to adapt better to different needs of consumers and different stresses on the skin in relation to the particular environment. In particular, significantly wider demands have been placed on skin care products for use in the workplace that go far beyond the scope of common household skin care products. According to W. Dicke (see W. Dicke; I. Funk-Stendel, B. Marschner, F. Zuther: “All about skin protection, skin cleansing, skin care”, 5th updated and expanded edition (115-118); October 2005) modern skin care products are preparations that contribute to the conservation and restoration of the physiological hydro-lipid emulsion in the upper skin layers. Skin care products often contain special ingredients that support the regeneration process of the skin. Accordingly, products for the care and/or health maintenance of the skin, as well as skin protection products, must be adapted, for example, to the demands of the workplace and to the degree of stress on the skin.
Since endogenous lipids and natural moisturising factors are extracted from the skin by repeated hand washing or working in a humid environment, the supply of moisture in skin care is of central importance. In this context, moisturising factors have the primary task of retaining moisture in the skin and slowing down evaporation of water from the skin. If these components are removed from the skin, there is an increased evaporation of water and the skin gives a dry and greasy impression, which can also be regarded as a precursor to degenerative dermatosis. Therefore, in addition to lipids and moisture, water-binding factors such as lactic acid are often used in skin care products also. If the skin care product is an oil-in-water emulsion, special requirements are placed on the formulation, because it can also lead to a drying of the skin when applying high water content emulsions due to a so-called “wick effect”. This must be taken into account in the development of a skin care product by combining different moisturising factors. Finally, with regard to the potential application of a skin protective product, acceptance of the product by the end consumer plays a key role. This means, in particular, that parameters such as absorption ability, the imprint behaviour, the ability to grip after application, oily sheen and the smell are paramount.
Also, in the decision made by an operation for a skin care product to use in the workplace, quite different, additional parameters over and above these play a crucial role. In addition to properties concerning care and protection of the skin against everyday work influences, the behaviour, for example, of the corresponding skin care product after application is crucial. After application of the skin care product, the treated areas of skin, especially the hands and forearms, come into contact inevitably with the working environment. The result of this is that surfaces of any kind at the workplace may be contaminated with unwanted residues from the skin care products through contact with treated areas of skin. This is especially critical if the contact is made with sensitive surfaces, products or production equipment. In the worst case, effects involving, for example, hydrophilic or emulsifying ingredients of skin care products on water-repellent surfaces, act in such a way on the surface in question that changes may be caused, such as in colour, consistency, or the chemical composition of surfaces. In addition, residues on workpieces or intermediate products can have a negative effect on the follow-up product. In addition, the creaming of hands with skin care products can affect the grip and thus make working with tools more dangerous.
There is therefore still a need for skin care products, that, on the one hand, meet the high demands of the consumer in terms of care and protection sufficiently and, on the other hand, correspond to the requirements of businesses by being universally applicable, without excessive consideration for any critical work environment and sensitive surfaces.